The SWR Spectre was the only choice in my opinion. My primary host guns are a Browning Buckmark with TacSol barrel and a Ruger 10/22. It is the highest db reduction for one. The other points that really seal the deal are:
-Removable Baffles:
It can be disassembled for cleaning. I feel that is very important because I like to keep all my gear squeaky clean. As we all know .22 is the dirtiest stuff you can buy. I also have found I shoot a whole lot of it when I can do it quietly and without hearing protection (more comfortable for long days in the back yard). I would never buy a tool I could not clean. Especially if it is intrinsically attached to a serial number and tax stamp - so therefore not practically replaceable.
-Multiple Calibers:
The ability to use the 17hmr and 5.7mm round is pretty sweet. That really makes it alot more versatile, especially if you do any small game hunting.
-Full Auto Capable:
I don't have the proper tax stamps at the moment but I may pursue that later. I would hate to have to buy another suppressor when I do that. The fact that they rate it for full auto also means they stand behind their products for "extreme use".
As a side note on any suppressor - be sure to take it apart and put anti-seize on the threads before the first use. You will thank me later on that one.
Just my $0.02.
RockGeek